CD123 Expression Is Associated With High-Risk Disease Characteristics in Childhood Acute Myeloid Leukemia: A Report From the Children's Oncology Group.

2021

JCO2101595

2021 Dec 02

1527-7755

<p><strong>PURPOSE: </strong>Increased CD123 surface expression has been associated with high-risk disease characteristics in adult acute myeloid leukemia (AML), but has not been well-characterized in childhood AML. In this study, we defined CD123 expression and associated clinical characteristics in a uniformly treated cohort of pediatric patients with newly diagnosed AML enrolled on the Children's Oncology Group AAML1031 phase III trial (NCT01371981).</p>

<p><strong>MATERIALS AND METHODS: </strong>AML blasts within diagnostic bone marrow specimens (n = 1,040) were prospectively analyzed for CD123 protein expression by multidimensional flow cytometry immunophenotyping at a central clinical laboratory. Patients were stratified as low-risk or high-risk on the basis of (1) leukemia-associated cytogenetic and molecular alterations and (2) end-of-induction measurable residual disease levels.</p>

<p><strong>RESULTS: </strong>The study population was divided into CD123 expression-based quartiles (n = 260 each) for analysis. Those with highest CD123 expression (quartile 4 [Q4]) had higher prevalence of high-risk rearrangements and -ITD mutations ( &lt; .001 for both) and lower prevalence of low-risk t(8;21), inv(16), and mutations ( &lt; .001 for all). Patients in lower CD123 expression quartiles (Q1-3) had similar relapse risk, event-free survival, and overall survival. Conversely, Q4 patients had a significantly higher relapse risk (53% 39%, &lt; .001), lower event-free survival (49% 69%, &lt; .001), and lower overall survival (32% 50%, &lt; .001) in comparison with Q1-3 patients. CD123 maintained independent significance for outcomes when all known contemporary high-risk cytogenetic and molecular markers were incorporated into multivariable Cox regression analysis.</p>

<p><strong>CONCLUSION: </strong>CD123 is strongly associated with disease-relevant cytogenetic and molecular alterations in childhood AML. CD123 is a critical biomarker and promising immunotherapeutic target for children with relapsed or refractory AML, given its prevalent expression and enrichment in patients with high-risk genetic alterations and inferior clinical outcomes with conventional therapy.</p>

10.1200/JCO.21.01595

J Clin Oncol

34855461

CEBPA bZip Mutations are Associated with Favorable Prognosis in de novo AML: A Report from the Children's Oncology Group.

2021

2021 May 05

1528-0020

<p>Bi-allelic CEBPA mutations are associated with favorable outcomes in AML. We evaluated the clinical and biologic implications of CEBPA-bZip mutations in childhood/young adult newly diagnosed AML. CEBPA-bZip mutation status was determined in 2,958 AML patients enrolled on COG trials (NCT00003790, NCT0007174, NCT00372593, NCT01379181). Next generation sequencing (NGS) was performed in 1,863 patients, 107 with CEBPA mutations, to characterize the co-occurring mutations. CEBPA mutational status was correlated with disease characteristics and clinical outcomes. CEBPA-bZip mutations were identified in 160/2958 (5.4%) patients, with 132 (82.5%) harboring a second CEBPA mutation (CEBPA-dm) and 28 (17.5%) with a single CEBPA-bZip only. The clinical and laboratory features of the two CEBPA cohorts were very similar. CEBPA-dm and CEBPA-bZip patients experienced identical event-free survival (EFS) of 64% and similar overall survival (OS) of 81% and 89%, respectively (p=0.259); this compared favorably to EFS and OS in CEBPA wild type (CEBPA-WT) of 46% and 61%, respectively (both p&lt;0.001). Transcriptome analysis demonstrated similar expression profiles for CEBPA-bZip and CEBPA-dm cases. Comprehensive NGS of CEBPA-mutant cases identified co-occurring CSF3R and GATA2 mutations in 13.1% and 21.5% of patients, respectively. Patients with dual CEBPA/CSF3R mutations had an EFS of 17% vs. 63% for CEBPA-mutant/CSF3R-WT (p&lt;0.001) with a corresponding relapse rate (RR) of 83% vs. 22%, respectively (p&lt;0.001); GATA2 co-occurrence did not impact outcome. CEBPA bZip domain mutations are associated with favorable clinical outcomes, regardless of mono or bi-allelic status. Co-occurring CSF3R and CEBPA mutations are associated with a high RR and nullifies the favorable prognostic impact of CEBPA mutations.</p>

10.1182/blood.2020009652

Blood

33951732